1. Field of the Invention
The present invention relates to a semiconductor integrated circuit, and more particularly, to a semiconductor integrated circuit having multi-gate transistor device integrated with other devices such as resistor and/or lateral double-diffused metal-oxide-semiconductor (hereinafter abbreviated as LDMOS) device.
2. Description of the Prior Art
Conventional planar metal-oxide-semiconductor (hereinafter abbreviated as MOS) transistor has difficulty when scaling down to 65 nm and below. Therefore the non-planar transistor technology such as Fin Field effect transistor (FinFET) technology that allows smaller size and higher performance is developed to replace the planar MOS transistor.
Since the manufacturing processes of the FinFET device are easily integrated into the traditional logic device processes, it provides superior process compatibility. More important, since the FinFET device increases the overlapping area between the gate and the substrate, the channel region is more effectively controlled. This therefore reduces drain-induced barrier lowering (DIBL) effect and short channel effect. In addition, the channel region is longer under the same gate length, and thus the current between the source and the drain is increased.
However, the FinFET device still faces many problems. For example, semiconductor structures of different sizes and isolation structures of different sizes are often formed on one semiconductor integrated circuit, and it is always difficult to construct and integrate those semiconductor structures and the isolation structures of different sizes on the same substrate. Furthermore, it is difficult for the circuit designer to construct above mentioned semiconductor integrated circuit without increasing process cost.